As the renewable energy market increases there is a dynamic balancing act that takes place every day between load, renewable power and conventional generation. For example, in the California energy market, solar energy use is significantly changing the dispatch of conventional generation. During the middle of the day, when load peaks, solar power is also at its peak and thus suppresses the traditional generation required during this peak load period. Consequently, there is a need to shift the power output from conventional generation to the morning and evening time, and reduce power, or shut off, during the middle of the day. Today, there is no energy storage system available that can shift the power output of conventional generation.
In California, thermal storage using inlet chilling has been one method of shifting the power of gas turbine generation, however, there are significant drawbacks to this chilling system. The first drawback is with respect to the charging time of a thermal storage system, which can take approximately 15-18 hours, and therefore can only discharge once per day. This can be overcome with larger chilling systems, however, such systems add considerable expense. The second drawback is that chillers work on the principal of cooling the inlet temperature of the gas turbine with a lower temperature limit of about 55 F, and, unfortunately, the peak power output is required typically between 5 am and 9 am and then again between 6 pm and 10 pm, which are out of phase with the hot part of the day.